CN103978147B - The progressive increment of a kind of radial forging is shaped the method for large tooth depth screw element - Google Patents

Abstract

The progressive increment of a kind of radial forging is shaped the method for large tooth depth screw element, radial compression amount is adopted to increase tup gradually, tup has screw thread form section, screw thread form comprises progressive increment change screw thread form section and the indeclinable screw thread form section of screw thread, multiple tups with progressive increment change screw thread form section synchronously forge, and workpiece rotates axial feeding simultaneously, reduces plastic force, reduce forging defect, improve surface accuracy and intensity; Equal-volume forges, and realizes near-net-shape, improves stock utilization, shortens the production cycle; The figuration manufacture of high-performance, major diameter, the greatly thread part such as leading screw, screw rod of tooth depth can be realized.

Description

A Method of Radial Forging Progressive Incremental Forming of Large Tooth Height Threaded Parts

technical field

The invention belongs to the technical field of advanced material forming, and in particular relates to a method for radially forging and incrementally forming large-tooth-height screw parts.

Background technique

Large-diameter, large-tooth-height threaded parts such as lead screws and screws are important functional components in the machinery industry. With the rapid development of my country's national economy, the demand for such large-diameter, large-tooth-height threaded parts is increasing, and the performance requirements are increasingly demanding. Traditional cutting-based processing methods are difficult to meet the high-efficiency, material-saving and high-performance processing and manufacturing of such parts.

Radial forging is a multi-directional local loading plastic forming technology, which is more efficient and material-saving than cutting processing, and plastic deformation can effectively increase the surface strength of parts and significantly improve the mechanical properties of products. Patent Application No. 201410012125.6 discloses a method of radially forging a lead screw. However, if this method is used to form threaded parts with large teeth, the amount of radial deformation will be large, resulting in high forming load, poor surface quality, and wear of the hammer head. exacerbated. Based on the radial forging forming screw method disclosed in the patent application number 201410012125.6, multi-pass radial forging and forming can reduce the amount of deformation in each pass, but the movement accuracy of rotary feed is required to be improved, and the multiple reciprocating rotation During the feed movement, the manipulators at both ends clamp and loosen multiple times, and the accumulation of errors will easily lead to the phenomenon of wrong and disordered teeth of the forged thread.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for radially forging incrementally forming large-tooth-height threaded parts. The radial compression amount is used to gradually increase the hammer head. The hammer head has a thread shape section, and the thread The shape includes the thread shape segment with gradual incremental change and the thread shape segment without thread change. Multiple hammers with thread shape segment with gradual incremental change are forged synchronously, and the billet is continuously rotated and fed, which reduces the forming force, reduces forging defects, and improves Surface accuracy and strength; equal-volume forging achieves near-net shape, improves material utilization, and shortens production cycle; can realize high-performance, large-diameter, large-tooth-height threaded parts such as lead screws and screws.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for radially forging incrementally forming large-tooth-height threaded parts, comprising the following steps:

Step 1, clamping the workpiece 2, one end of the workpiece 2 is clamped by the first manipulator 1;

Step 2, the workpiece 2 is fed axially, the first manipulator 1 clamps the workpiece 2 and feeds it in the direction of the radial forging hammer 3, the hammer 3 has a thread shape segment, and the thread shape segment includes a progressive incremental change thread shape segment and For the thread shape section that does not change the thread, the formed thread section on the workpiece 2 is close to the end of the hammer head 3, and is aligned with the end of the thread shape section on the hammer head 3 that is close to the workpiece 2;

Step 3, the workpiece 2 is rotated and fed;

The workpiece 2 is rotated at an angle θ, and is fed axially at the same time; the number of hammer heads 3 is N, N=2～8, and the rotation angle θ should satisfy

The rotation speed of workpiece 2 is ω, the axial feed speed is v, and the feed speed v should satisfy $v=\frac{\mathrm{P\ω}}{2\mathrm{\π}};$

In the formula, P is the lead of the thread to be formed on the workpiece 2;

Step 4, strike forging with hammerhead 3;

Step 5, the hammer head 3 is lifted;

Step 6, repeat steps 3 to 5, the workpiece 2 is continuously rotated and fed, and the hammer head 3 is continuously struck and lifted, so that 2/3 to 3/4 of the formed thread section on the workpiece 2 is formed into a thread shape;

Step 7, the second manipulator 4 clamps the other end of the workpiece 2, and the first manipulator 1 releases and exits;

Step 8, repeat steps 3 to 5, the workpiece 2 is continuously rotated and fed, and the hammer head 3 is continuously struck and lifted, so that the unformed part of the formed thread section on the workpiece 2 is formed into a thread shape;

Step 9, the workpiece 2 is clamped by the second manipulator 4 and quickly fed in the axial direction, and unloaded.

The hammer head 3 has a thread shape segment with progressive incremental change and a thread shape segment with a constant thread change; Incremental change thread shape segments are different;

The first kind of hammer head 3a has a thread shape section a, and the thread shape section a includes a thread shape section a ₁ with a gradual incremental change and a thread shape section a ₂ that the thread does not change; the pitch diameter and minor diameter of the thread in the a ₁ section and a ₂ section The position is the same, but the thread profile of stage a ₁ is incomplete, the thread profile of stage a ₂ is a complete thread profile, the thread profile of stage a ₁ increases gradually along the direction of stage a ₁ to stage a ₂ , and the tooth profile gradually completes; a ₁ stage The first-stage thread addendum height and a2 _- stage thread addendum stroke α taper; when the first type of hammer head 3a hits forging, the radial forging amount of a1 _- stage gradually increases along the direction of a1 _- stage to a2 _- stage; a1 _- stage length It is 3/5 of the total length of the thread shape section a, and the length of a ₂ section is 2/5 of the total length of the thread shape section a;

The second kind of hammer head 3b has a thread shape section b, and the thread shape section b includes a thread shape section b ₁ with a gradual incremental change and a thread shape section b ₂ that the thread does not change; the b ₁ section and the b ₂ section are all complete thread teeth Type b, segment b is composed _of complete thread tooth shapes arranged continuously according to the conical shape, segment b is the pitch diameter of the thread _of segment b and segment b is the β taper of the pitch diameter of the thread of segment b; when the _second type of hammer head 3b strikes forging, b is the diameter _of segment b _The amount of forging gradually increases along the direction of b1 to b2 _; the length of b1 is 3/5 _of the total length _of the thread shape segment b, and the length of b2 is 2/5 of the total length of the thread shape b.

The invention adopts the radial forging method to progressively and incrementally form threaded parts such as screw and screw; Feed, the hammer hits the forging, the hammer is lifted, and the above process is repeated continuously, and the thread profile on the workpiece is gradually forged. The forming force is small, it is not easy to produce forging defects, the forming accuracy is high, and the surface quality is good; the metal fibers of the parts are along the screw The surface shape is continuously distributed, and the plastic deformation increases the surface strength and hardness of the lead screw; reduces the forming time, improves the forming quality and performance; can process and manufacture threaded parts with high performance, large diameter, and large tooth height.

Description of drawings

Figure 1 is a schematic diagram of the connection of the device used in the present invention.

Fig. 2 is an axonometric view of the cutting hammer head 3a in the present invention.

Fig. 3 is a cross-sectional view of a cutting hammer 3a in the present invention.

Fig. 4 is a perspective view of the progressive hammer head 3b in the present invention.

Fig. 5 is a cross-sectional view of the progressive hammer head 3b in the present invention.

Fig. 6 is a schematic diagram of the rotary feeding of the workpiece 2 according to the present invention.

Fig. 7 is a schematic diagram of percussion forging of the hammer head 3 of the present invention.

Fig. 8 is a schematic diagram of lifting the hammer head 3 of the present invention.

FIG. 9 is a schematic diagram of the second manipulator 4 clamping the other end of the workpiece 2 according to the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Embodiment one

A method for radially forging incrementally forming large-tooth-height threaded parts, comprising the following steps:

Step 1, clamping the workpiece 2, referring to Figure 1, one end of the workpiece 2 is clamped by the first manipulator 1;

Step 2, the workpiece 2 is fed axially, the first manipulator 1 clamps the workpiece 2 and feeds it in the direction of the radial forging hammer 3, the hammer 3 has a thread shape segment, and the thread shape segment includes a progressive incremental change thread shape segment and For the thread shape section that does not change the thread, the formed thread section on the workpiece 2 is close to the end of the hammer head 3, and is aligned with the end of the thread shape section on the hammer head 3 that is close to the workpiece 2;

The hammer head 3 has a thread shape section with gradual incremental changes and a thread shape section with no thread change; The thread shape sections are different; the present embodiment adopts the first hammer head 3a;

Referring to Fig. 2 and Fig. 3, the first type of hammer head 3a has a thread shape section a, and the thread shape section a includes a thread shape section a ₁ with a gradual incremental change and a thread shape section a ₂ that does not change in the thread; a ₁ section and a _{2 The} positions of pitch diameter and minor diameter of section a are the same, but the thread profile _of section a1 is incomplete, section a2 is _a complete thread profile, and the thread profile of section a1 increases gradually along the direction _of section _a1 to section a2. The tooth shape is gradually complete; a _1st stage of thread addendum height and a _2nd stage of thread addendum travel α taper; when the hammer head 3a strikes forging, the radial forging amount of a _1st stage gradually increases along the direction of a _1st stage to a _2nd stage; a The length of ₁ section is about 3/5 of the total length of the thread shape section a, and the length of the ₂ sections is about 2/5 of the total length of the thread shape section a;

Step 3, referring to Fig. 6, the workpiece 2 is rotated and fed;

The workpiece 2 is rotated at an angle θ, and is fed axially at the same time; the number of hammer heads 3 is N, N=2～8, and the rotation angle θ should satisfy

The rotation speed of workpiece 2 is ω, the axial feed speed is v, and the feed speed v should satisfy

In the formula, P is the lead of the thread to be formed on the workpiece 2;

Step 4, referring to Figure 7, the hammer head 3 strikes forging;

Step 5, referring to Figure 8, the hammer head 3 is lifted;

Step 6, repeat steps 3 to 5, the workpiece 2 is continuously rotated and fed, and the hammer head 3 is continuously struck and lifted, so that 2/3 to 3/4 of the formed thread section on the workpiece 2 is formed into a thread shape;

Step 7, referring to FIG. 9, the second manipulator 4 clamps the other end of the workpiece 2, and the first manipulator 1 releases and exits;

Step 8, repeat steps 3 to 5, the workpiece 2 is continuously rotated and fed, and the hammer head 3 is continuously struck and lifted, so that the unformed part of the formed thread section on the workpiece 2 is formed into a thread shape;

Step 9, the workpiece 2 is clamped by the second manipulator 4 and quickly fed in the axial direction, and unloaded.

Embodiment two

A method for radially forging incrementally forming large-tooth-height threads, comprising the following steps:

Step 1, clamping the workpiece 2, referring to Figure 1, one end of the workpiece 2 is clamped by the first manipulator 1;

Step 2, the workpiece 2 is fed axially, the first manipulator 1 clamps the workpiece 2 and feeds it in the direction of the radial forging hammer 3, the hammer 3 has a thread shape segment, and the thread shape segment includes a progressive incremental change thread shape segment and For the thread shape section that does not change the thread, the formed thread section on the workpiece 2 is close to the end of the hammer head 3, and is aligned with the end of the thread shape section on the hammer head 3 that is close to the workpiece 2;

The hammer head 3 has a thread shape section with gradual incremental changes and a thread shape section with no thread change; The thread shape sections are different; the present embodiment adopts the second hammerhead 3b;

Referring to Fig. 4 and Fig. 5, the second type of hammer head 3b has a thread shape segment b, and the thread shape segment b includes a thread shape segment b ₁ with a gradual incremental change and a thread shape segment b ₂ whose thread does not change; b ₁ segment and b ₂ The first section is a complete thread profile, b ₁ section is composed of complete thread tooth profiles arranged continuously according to the conical shape, b ₁ section thread pitch diameter and b ₂ section thread pitch β taper; when the hammer head 3b strikes forging, b The radial forging amount of section ₁ gradually increases along the direction of section b ₁ to section b ₂ ; the length of section b ₁ is about 3/5 of the total length of thread shape section b, and the length of section b ₂ is about 2/5 of the total length of thread shape section b;

Step 3, referring to Fig. 6, the workpiece 2 is rotated and fed;

The workpiece 2 is rotated at an angle θ, and is fed axially at the same time; the number of hammer heads 3 is N, N=2～8, and the rotation angle θ should satisfy

The rotation speed of workpiece 2 is ω, the axial feed speed is v, and the feed speed v should satisfy

In the formula, P is the lead of the thread to be formed on the workpiece 2;

Step 4, referring to Figure 7, the hammer head 3 strikes forging;

Step 5, referring to Figure 8, the hammer head 3 is lifted;

Step 6, repeat steps 3 to 5, the workpiece 2 is continuously rotated and fed, and the hammer head 3 is continuously struck and lifted, so that 2/3 to 3/4 of the formed thread section on the workpiece 2 is formed into a thread shape;

Step 7, referring to FIG. 9, the second manipulator 4 clamps the other end of the workpiece 2, and the first manipulator 1 releases and exits;

Step 8, repeat steps 3 to 5, the workpiece 2 is continuously rotated and fed, and the hammer head 3 is continuously struck and lifted, so that the unformed part of the formed thread section on the workpiece 2 is formed into a thread shape;

Step 9, the workpiece 2 is clamped by the second manipulator 4 and quickly fed in the axial direction, and unloaded.

Claims (2)

1. A method for radially forging incrementally forming large-tooth-height threaded parts, characterized in that, comprising the steps: Step 1, clamping the workpiece (2), one end of the workpiece (2) is clamped by the first manipulator (1); Step 2, the workpiece (2) is fed axially, the first manipulator (1) clamps the workpiece (2) and feeds it in the direction of the radial forging hammer head (3), the hammer head (3) has a thread shape section, the thread shape The segment includes a thread shape segment with gradual incremental change and a thread shape segment with no thread change. The thread segment to be formed on the workpiece (2) is close to the end of the hammer head (3), and the thread shape segment on the hammer head (3) is close to the workpiece (2). aligned at one end; Step 3, the workpiece (2) is rotated and fed; The workpiece (2) is rotated at an angle θ, and is fed axially at the same time; the number of hammer heads (3) is N, N=2～8, and the rotation angle θ should satisfy The rotation speed of the workpiece (2) is ω, the axial feed speed is v, and the feed speed v should satisfy $v=\frac{P\mathrm{\ω}}{2\mathrm{\π}};$ In the formula, P is the lead of the thread to be formed on the workpiece (2); Step 4, the hammer head (3) strikes forging; Step 5, the hammer head (3) is lifted; Step 6, repeat steps 3 to 5, the workpiece (2) is continuously rotated and fed, and the hammer head (3) is continuously struck and lifted, so that 2/3 to 3/4 of the formed thread section on the workpiece (2) is partially formed into threads shape; Step 7, the second manipulator (4) clamps the other end of the workpiece (2), and the first manipulator (1) releases and exits; Step 8, repeat steps 3 to 5, the workpiece (2) is continuously rotated and fed, and the hammer head (3) is continuously struck and lifted, so that the unformed part of the formed thread section on the workpiece (2) is formed into a thread shape; In step 9, the workpiece (2) is clamped by the second manipulator (4) and quickly fed in the axial direction and unloaded. 2. A method of radially forging and incrementally forming large-tooth-height threaded parts according to claim 1, characterized in that: the hammer head (3) has a thread shape section with gradual incremental changes and a thread that does not change The thread shape segment; the hammer head (3) has two structures: the first type hammer head (3a) and the second type hammer head (3b), the difference is that the thread shape segments with gradual incremental changes are different, and there are many joint effects The structural forms of the two tups are the same, being one of the first tup and the second tup; The first type of hammer head (3a) has a thread shape section a, and the thread shape section a includes a thread shape section a ₁ with a gradual incremental change and a thread shape section a ₂ where the thread does not change; the thread pitch diameters of the a ₁ section and a ₂ section , The position of the small diameter is the same, but the thread profile of section a ₁ is incomplete, the thread profile of section a ₂ is a complete thread profile, and the thread profile of section a _{1 increases gradually along the direction from section a 1 to} section a ₂ , and the tooth profile gradually completes; a _1st stage thread tooth top and a _2nd stage thread tooth top are in α taper; when the first type of hammer head (3a) strikes forging, the radial forging amount of a _1st stage gradually increases along the direction of a _1st stage to a _2nd stage; a The length of the _first section is 3/5 of the total length of the thread shape section a, and the length of the _second section is 2/5 of the total length of the thread shape section a; The second type of hammer head (3b) has a thread shape segment b, and the thread shape segment b includes a thread shape segment b ₁ with a gradual incremental change and a thread shape segment b ₂ where the thread does not change; the threads of the b ₁ segment and the b ₂ segment are both Complete thread profile, segment b ₁ is composed of complete thread profiles arranged continuously in a conical shape, the pitch diameter of segment b ₁ and pitch diameter of segment b ₂ are β-tapered; when the second type of hammer (3b) strikes forging, The radial forging amount of section b ₁ gradually increases along the direction from section b ₁ to section b ₂ ; the length of section b ₁ is 3/5 of the total length of thread shape section b, and the length of section b ₂ is 2/5 of the total length of thread section b.